Hardwood Flooring and Humidity

Monday October 27, 2008
Article Word Count:399 Comments (8) Permalink

When it comes to extreme low or high humidity, flooring made from wood and/or natural materials generally suffers the most damage. This includes floor types such as: hardwood, bamboo, cork and even laminate.

Trees need water to survive; the exact opposite is true of wood floors. In fact, the combination of water and wood flooring can lead to damage that can cost a fortune to fix. Even a small increase in humidity can cause hardwood flooring to expand. And the terrible part is - the effects may not be noticeable until it's too late.

The Relationship of Wood and Water

First and foremost, it's important you understand the relationship between wood and water. Trees contain vertically-aligned fibers, also known as vessels, that work in similar function to a soda straw. These vessels draw water from the ground and transport it up to the tree's branches. Although these fibers dry up once the wood is cut, they can still absorb water and moisture from the air. This characteristic is the reason floors made with wood materials expand and contract in low humidity and swell in high humidity.

Moisture Content

The durability of hardwood floors is measured by its moisture content; in other words, the amount of water a particular wood can carry. Some types can hold up to 200% of its actual wood weight! Once the wood has been cut, it's dried and typically kept in a room with a 30% humidity level. At this level, most woods are very stable. Any change below or above 30% may cause wood to either shrink or swell.


Preventative measures should be taken before and during the installation process in order to reduce the risk of moisture damage. Letting your floors acclimate (adjust) to your home environment is an essential part of the process. Allowing your wood floors to stabilize will help ensure less floor movement during and after installation.

Acclimation could take anywhere from a few hours to a week, depending on climate and temperature of your home, and the moisture content of the wood. To determine an accurate acclimation length, consult your manufacturer (or manufacturer's guidelines). Most flooring professionals should be able to establish the moisture content of the hardwood upon delivery and let you know how long it will take to acclimate.


About the author:
Comments (8)

Talkback – Leave a commentThere are 8 comments

question on using a steam mop
Hi, When you have a wood floor that is put together via tongue and groove, would you consider that sealed? I love the Shark steam mop but don't want to ruin the floor. My sister-in-law has a wood floor similar to mine and has been using her steam mop for over a year, and hasn't had a problem. However, when I contacted Mohawk, they say only on sealed hardwoods. Is that a wood floor that is not tongue and groove and that has the polyurethane coating put on it. Thanks for your help.
June 25 2010
what is happening, my brazillian walnut floor is about a year old. In the middle of the summer I started to see gaps between the boards, and it appears to be bowing up on the outside edges??? The humidity in the house is 72%---that is high, but I'm afraid to lower it it, that the gaps will increase.
October 17 2009
WE have recently purchased a two story lake house on Compass lake in Alford, FL (panhandle) an would like to install laminiate flooring (looks like wood) on the upper floor. We have heard that some laminiate planks are not good for our area. We have heard of a company called BKR or BRK flooirng out of Texas that has a laminaite good for humiidty since we won't have HVAC on all of the time. Can you give us any advise, please. We need to decide on the flooirng VERY SOON! Help Thanks
April 27 2009
Glue Down Floor Question
I have new glue down floors and there is what appears to be a residue on them but it can not be cleaned off. Someone told me this may be due to moisture from the concrete under the floor. Is this possible?
April 17 2009
Best Humidity Level
I live in Michigan and have a large room (28x30) that is covered with hardwood flooring. I want to set my humidity controls for the best humidity level for the flooring. What is that value.
November 23 2008
So that is why my hardwood floors are developing gaps between the boards. I will try a humidifier in the room. Thanks for the info
October 30 2008
I usually recommend that my clients invest in moisture meters to monitor the humidity in their rooms. If necessary, you can use a dehumidifier or humidifier to control humidity levels. You can also all a fish tank or a water fountain to increase humidity in a room, but these are harder to control humidity levels.
October 29 2008
Thanks for the education. I am enjoying learning all about hardwood on this site. You have a ton of helpful info
October 28 2008
Post a Comment

Post a Comment

Please click the black box below to show the submit button: